This invention relates generally to rotator cuff repair, and more particularly, to the use of engineered tissues in conjunction with such treatment.
Intervertebral discs provide mobility and a cushion between the vertebrae. At the center of the disc is the nucleus pulposus. The nucleus pulposus is surrounded by the annulus fibrosis, which is comprised of cells (fibrocyte-like and chondrocyte-like), collagen fibers, and non-fibrillar extracellular matrix. The components of the annulus are arranged in 15-25 lamellae around the nucleus pulposus. The fibers in the lamellae alternate their direction of orientation by 30 degrees between each band.
The annulus fibrosis has three important functions. First, the annulus contains the nucleus pulposus. Second, the annulus fibrosis, with other ligaments, connects the vertebrae of the spine. Lastly, the annulus fibrosis helps to control movement between the vertebrae.
The fibers of the annulus can tear causing pain and possible extrusion of the nucleus pulposus. Extrusion of the nucleus pulposus is known as a disc herniation. Disc herniations can compress nerves or the spinal cord resulting in arm or leg pain and dysfunction. Surgery to repair disc herniations leaves a hole in the annulus fibrosis. The hole in the annulus acts as a pathway for additional material to protrude into a nerve, resulting in a recurrence of the herniation.
To date, the treatment of tears or defects of the annulus fibrosis has relied for the most part on eliminating the defective disc or disc function. This may be accomplished by fusing the vertebra on either side of the disc. In terms of replacement, prior-art techniques replace either the nucleus or the nucleus and annulus functions. My co-pending U.S. patent application Ser. No. 09/322,516, and Patent Cooperation Treaty Application Serial No. PCT/US/14708 describe methods and devices to occlude annular defects.
Certain of my co-pending patent applications and issued patents referenced above disclose the repair of tissues and organs by adding live cells to the extracellular matrix of tissues or organs harvested to recently deceased human or animals. For example, with respect to intervertebral disc repair, fibrocytes, annulus fibrosis cells, cells that differentiate into annulus fibrosis cells, or cells that function like annulus fibrosis cells are harvested and combined with the extracellular matrix of the annulus fibrosis from a recently deceased human or animal to produce an engineered annulus fibrosis.
This previously disclosed invention is not limited to treatment of the intervertebral disc. For example, the invention could also be used to treat other tissues of the body such as the meniscus of the knee. In like fashion, the processes described herein may be used to repair or replace other tissues or organs of the body such as the pancreas, liver, kidney, heart, etc. Healthy live cells would be obtained thorough biopsy and tissue culture. The live cells would be added to the extracellular matrix of tissues or organs harvested to recently deceased human or animals.
According to this invention, living cells are combined with rotator cuff extracellular matrix obtained from recently deceased human or animal donors to create engineered rotator cuff tissue. In the preferred embodiment, fibrocytes from a living donor, preferably the patient, and rotator cuff tissue is harvested from a recently deceased human or animal donor in a manner which retains the extracellular matrix. Precursor or developed rotator cuff cells, chondrocytes, or other living cells that could function like rotator cells or that could differentiate into cells to build a functional rotator cuff may also be used. The harvested cells are combined with the extracellular matrix to produce an engineered rotator cuff tissue, which is then transplanted into or onto a patient""s rotator cuff to be repaired.
Additional therapeutic substances such as culture medium, growth factors, differentiation factors, hydrogels, polymers, antibiotics, anti-inflammatory medications, or immunosuppressive medications could be added to the transplanted annulus fibrosis tissue. In like fashion, the processes described herein may be used to repair or replace other tissues or organs of the body such as the pancreas, liver, kidney, heart, etc. Healthy live cells would be obtained thorough biopsy and tissue culture. The live cells would be added to the extracellular matrix of tissues or organs harvested to recently deceased human or animals.
The cells or engineered tissues may be introduced using any surgical technique, including percutaneous or laparoscopic approaches. As one delivery mechanism, a passageway may be formed through the shoulder, with the cells or engineered rotator cuff tissue being introduced through the passageway. In particular, the engineered tissue may be sewn or otherwise adhered to the inside or outside of the existing annulus rotator cuff using standard surgical procedures.